Most everyone has faced the need for an extra bed or mattress at some time in their life. Air mattresses, originally introduced many years ago, have allowed homeowners and others to provide their guests with a surface more comfortable than sleeping on the floor, while not imposing the same storage requirements as traditional mattresses.
While air mattresses are a significant improvement over sleeping on the ground or curled up on a sofa, the mattresses still have many problems. For example, air mattress designs were clunky and uncomfortable, the manufacturing techniques and materials used resulted in poor air retention, the inflation and deflation systems employed with such mattresses often required significant time and effort, and the mattresses tended to provide only marginal support.
Some issued patents, such as U.S. Pat. No. 4,977,633, issued to Robert B. Chaffee on Dec. 18, 1990 (“the Chaffee patent”), and U.S. Pat. No. 5,960,495, issued to Yaw-Yuan Hsu, et al. on Oct. 5, 1999 (“the Hsu patent”), have attempted to address some of these shortcomings. By way of example, the Chaffee patent teaches the use of a large, manually operated pressure release valve to speed deflation. The Chaffee patent also teaches the inclusion of a small cylinder around which a deflated bed can be rolled, further simplifying deflation. This same arrangement also allows the bed to automatically unroll while being inflated, which also simplifies the inflation process. The Chaffee patent also illustrates the inclusion of an electric motor, which speeds the inflation process.
The Hsu patent attempts to address some of the comfort problems typically associated with air mattresses. The Hsu patent utilizes tube beams inside a mattress to provide additional lateral load support. These tube beams are separate structures which are added to the inside of the mattress and are attached to the upper and lower mattress surfaces through a sinusoidal sealing pattern in an attempt to provide further rigidity to the mattress.
A person sleeping on mattresses such as those described in the Chaffee and Hsu patents still has the perception of sleeping on the floor. Furthermore, getting into and out of such a bed can be difficult, especially for an elderly or disabled person.
A solution to this problem is to provide a mattress that approximates the dimensions of a traditional bed. But, such inflatable mattresses have a propensity to roll over. Rollovers are not only a problem with inflatable mattresses, but with all lightweight support surfaces, such as inflatable furniture. Some in the prior art, such as U.S. Pat. No. 6,161,902, issued to Marvin S. Lieberman on Dec. 19, 2000 (the Lieberman patent); the “Game Day Minute Chair” by Aero Products International, Inc. of Wauconda, Ill.; and the “Retro Air Chair” by Intex Recreation Corporation of Long Beach, Calif., have used multiple inflatable cylindrical tubes to improve the stability of inflatable chairs.
While the stabilization methods employed in the prior art can improve overall chair stability, each has shortcomings, especially when applied to other support systems. For example, the Lieberman patent teaches the installation of a “U” shaped inflatable tube underneath the front of a chair and a small inflatable tube extending along and immovably attached to the rear base of the chair. Each of these tubes is also inflated separately from and to a higher pressure than the body of the chair. The increased pressure of these tubes strengthens the base of the chair, thus reducing the likelihood of rollover. While this approach has some merit, the introduction of separately inflatable tubes means added work for the consumer, who must move an inflation device from one valve to another until the chair is properly filled.
The Game Day Minute Chair and Retro Air Chair apply alternative stabilization techniques. In both cases, two small inflatable stabilizer bars, no more than fifteen inches long and approximately six inches in diameter when inflated, are attached to the base of the chair to increase the surface area covered by the chair. These stabilizer bars are attached to the chair through narrow, short inflator tubes (three and one half inches long by one and one half inch wide in the case of the Game Day Minute Chair). The inflator tubes allow the stabilizer bars to be in fluid communication with the chair bodies and to fill with air as the chair is filled. The increased surface area created by the combination of the inflator tubes and the stabilizer bars provides more stability by distributing the weight over a larger area.
As with the Lieberman patent, the shape and position of the stabilizer bars employed on these chairs also strengthens the chair body where the stabilizer bars contact the chair. However, such strengthening is only provided to areas adjacent to the tubes. While this may be practical for inflatable support systems with smaller weight bearing surfaces, such as chairs, a few, relatively short stabilizer bars will not provide stability for larger inflatable support systems, such as inflatable mattresses.
An additional problem faced by inflatable support systems of the prior art is structural stability of the sides of the support system. The shape of the side tends to distort as weight is applied at or near the edge of the support system. Such distortion can cause a person to slip or fall from the support surface, increasing the risk of injury to a user. This problem becomes increasingly significant as the height of the support system is increased. A means of improving the structural stability of the side of the mattress is therefore preferable as height is increased.